Network Communication with Client-Forced Authentication

1. A method for establishing an authenticated connection between a client and a server under the Hypertext Transfer Protocol (HTTP), comprising: preparing a HTTP connection request packet containing authentication request data for requesting establishment of an authenticated network connection under HTTP, the authentication request data formatted for prompting a server recognizing said data to respond with a first predefined message and for causing a server not recognizing said data to respond with a second pre-defined message; sending the HTTP connection request packet to the server; receiving a HTTP response packet containing a response message from the server responding to the HTTP connection request packet; if the HTTP response message includes the first pre-defined message, transmitting credential data of the client in subsequent HTTP packets to the server for authentication; if the HTTP response message includes the second pre-defined message, transmitting subsequent communication to the server over a non-authenticated HTTP connection.

2. A method as recited in claim 1 , further comprising: if the HTTP response message includes a third predefined message indicating that the client has an existing authenticated HTTP connection with the server, transmitting subsequent communication to the server over the existing authenticated HTTP connection.

3. A method as recited in claim 1 , further comprising: identifying from the HTTP response packet an authentication protocol supported by the server; and communicating with server, including said transmitting credential data, to perform authentication of the client under the authentication protocol.

4. A method as recited in claim 1 , wherein the authentication request data are included in a header portion of the HTTP connection request packet.

5. A method as recited in claim 4 , wherein the authentication request data identify a method defined in the Hypertext Transfer Protocol (HTTP).

6. A method as recited in claim 1 , wherein each of the HTTP connection request and HTTP response packets contains a data portion containing communication data formatted according to a second communication protocol, and wherein the authentication request data are in the data portion of the HTTP connection request packet.

7. A method as recited in claim 6 , wherein the second communication protocol is the Internet Printing Protocol (IPP).

8. A system for establishing an authenticated connection between a client and a server under the Hypertext Transfer Protocol (HTTP), comprising: means for preparing an HTTP connection request packet containing authentication request data for requesting establishment of an authenticated network connection under HTTP, the authentication request data formatted for prompting a server recognizing said data to respond with a first predefined message and for causing a server not recognizing said data to respond with a second pre-defined message; means for sending the HTTP connection request packet to the server; means for receiving a HTTP response packet containing a response message from the server responding to the HTTP connection request packet; means for transmitting credential data of the client in subsequent HTTP packets to the server for authentication if the HTTP response message includes the first pre-defined message; and means for transmitting subsequent communication to the server over a non-authenticated HTTP connection if the HTTP response message includes the second pre-defined message.

9. A system as recited in claim 8 , further comprising: means for transmitting subsequent communication to the server over the existing authenticated HTTP connection if the HTTP response message includes a third predefined message indicating that the client has an existing authenticated HTTP connection with the server.

10. A system as recited in claim 8 , further comprising: means for identifying from the HTTP response packet an authentication protocol supported by the server; and means for communicating with the server, including said transmitting credential data, to perform authentication of the client under the authentication protocol.

11. A system as recited in claim 8 , wherein the authentication request data are included in a header portion of the HTTP connection request packet.

12. A system as recited in claim 11 , wherein the authentication request data identify a method defined in the Hypertext Transfer Protocol (HTTP).

13. A method as recited in claim 8 , wherein each of the HTTP connection request and HTTP response packets contains a data portion containing communication data formatted according to a second communication protocol, and wherein the authentication request data are in the data portion of the HTTP connection request packet.

14. A method as recited in claim 13 , wherein the second communication protocol is the Internet Printing Protocol (IPP).